Francis j



UNITED STATES PATENT OFFICE.

FRANCIS J. CLAMER, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE AJAX LEAD COATING COMPANY, OF SAME PLACE.

PROCESS OF COATING METAL.

SPECIFICATION forming part of Letters Patent No. 451,592, dated May 5, 1891.

Application filed April 30, 1890. Serial No, 350,054. (No specimens.) 7

T to whom it may concern.-

Be it known that I, FRANCIS J CLAMER, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Coating Metals; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to the art of coating metals, and has for its obj eet the provision of a process for preparing and coating plates and other metallic articles, whereby they are thoroughly cleaned and coated.

In the ordinary process of coating metals the plates or other articles are firstimmersed in a pickle or bath made of sulphuric acid and water, and when taken out are rinsed in water. This treatment leaves upon the articles a deposit of sulphureted hydrogen,

which prevents a proper union of the coating metal with the plate or other article. I remove the sulphureted hydrogen by immersing the plate or other article in a bath of muriatic acid. I find, also, that plates and other articles treated under my patent, No. 363,593,0f May 24, 1887, in which they are made the negative pole of an electric current in a cyanide bath, have a deposit of cyanide of iron upon them when they are removed from the 'bath,which prevents the proper adhesion of the coating metal. This may also be removed by immersing the plates in the muriatic-acid bath, as in the previous case, when taken from the sulphuric-acid bath. After removing the plates or other articles from the muriatic-acid bath, whether the same succeeds one or the other of the cleansing-baths above referred to, I then immerse them in or coat them lightly with a bath made of a saturated solution of tin, zinc, and muriatie acid, which is formed of equal parts of tin and zinc dissolved in muriatic aid in sufficient quantity to saturate the muriatic acid. To get the best effects from this bath,

the zinc and tin are first melted together and more readily soluble in the muriatic acid. The immersion or coating in this bath gives the plates a slight covering of the saturated solution, which forms a very receptive and adhesive surface for the succeeding metal bath, into which latter they are immersed after being removed from the saturated solution bath. The coating-bath which I use is that produced under my patent, No. 283,077, of August 14:, 1883, and is formed of ordinary pig-lead having mingled with it sal-ammoniac, arsenic, phosphate of lead or phosphorus, and a suitable. flux, such as borax.

To make the bath I add to every one hundred pounds of lead while in a molten state three (3) ounces (more or less) of sal-ammoniac, half (a) ounce (more or less) of arsenic; three (3) ounces (more or less).of phosphate of lead or phosphorus, and half (e) an ounce, (more or less) of borax or a similar flux. In addition to the matter set out in said Patent- No. 283,077, I may also add a small per cent. of the saturated solution of tin, zinc, and muriatic acid, which may be mixed with sal-ammoniac.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is-

The herein-described process of preparing and coating metal plates and other metal articles, consisting in cleansing them in a suitable cleansing-bath, then immersing them in a bath of muriatic acid, then immersing or coating them in a bath of saturated solution of tin, zinc, and muriatic acid, and finally coating them in a bath composed of lead, salammoniac, arsenic, and phosphate of lead or phosphorus, substantially as and for the purpose set forth.

In testimony whereof I affix mysignature in presence of two witnesses.

FRANCIS J. CLAMER. Witnesses:

F. T. F. JOHNSON, I. N. KALB. 

